Joshua Gross
0a6f4dd8aa
Summary: Ensure that on Android, only Scheduler and UIManagerBinder directly retain UIManager. These existing JSI function-retained lambdas will not have owning share_ptr refs to UIManager, just raw pointers. By the time the VM deallocates all JSI objects and UIManagerBinding goes away, it should be able to deallocate UIManager synchronously when UIManagerBinding is deallocated. The VM should not be executing any of these JSI functions at that time, so this should ensure that the raw pointer access is safe. This should also provide some extremely small perf wins, and make our memory model easier to reason about, since we're using shared_ptr less often and now `UIManager` is only owned in two places: Scheduler and UIManagerBinding. So, there are now only two places where UIManager can be deallocated: 1) Hermes is deallocated first, and UIManagerBinding is deallocated before Scheduler. Scheduler holds onto UIManager. Scheduler later is deallocated and frees UIManager; this would cause a crash if it's not completed before Hermes is torn down, but we currently ensure that Scheduler is torn down before Hermes. This is fine but we should document this contract, or make Scheduler not own UIManager. 2) Scheduler is deallocated first, decrementing the shared_ptr to UIManager. Later Hermes is torn down, which deallocates UIManagerBinding via the JSI pointer table, which synchronously deallocates UIManager before Hermes has shut down. This is the desired outcome. Changelog: [[Internal]] Reviewed By: shergin Differential Revision: D17872586 fbshipit-source-id: cbb25b5cd025f5f8597dc7a66073fe64edc57aa8
React Native
Learn once, write anywhere:
Build mobile apps with React.
Getting Started · Learn the Basics · Showcase · Contribute · Community · Support
React Native brings React's declarative UI framework to iOS and Android. With React Native, you use native UI controls and have full access to the native platform.
- Declarative. React makes it painless to create interactive UIs. Declarative views make your code more predictable and easier to debug.
- Component-Based. Build encapsulated components that manage their own state, then compose them to make complex UIs.
- Developer Velocity. See local changes in seconds. Changes to JavaScript code can be live reloaded without rebuilding the native app.
- Portability. Reuse code across iOS, Android, and other platforms.
React Native is developed and supported by many companies and individual core contributors. Find out more in our ecosystem overview.
Contents
- Requirements
- Building your first React Native app
- Documentation
- Upgrading
- How to Contribute
- Code of Conduct
- License
📋 Requirements
React Native apps may target iOS 9.0 and Android 4.1 (API 16) or newer. You may use Windows, macOS, or Linux as your development operating system, though building and running iOS apps is limited to macOS. Tools like Expo can be used to work around this.
🎉 Building your first React Native app
Follow the Getting Started guide. The recommended way to install React Native depends on your project. Here you can find short guides for the most common scenarios:
📖 Documentation
The full documentation for React Native can be found on our website.
The React Native documentation discusses components, APIs, and topics that are specific to React Native. For further documentation on the React API that is shared between React Native and React DOM, refer to the React documentation.
The source for the React Native documentation and website is hosted on a separate repo, @facebook/react-native-website.
🚀 Upgrading
Upgrading to new versions of React Native may give you access to more APIs, views, developer tools and other goodies. See the Upgrading Guide for instructions.
React Native releases are discussed in the React Native Community, @react-native-community/react-native-releases.
👏 How to Contribute
The main purpose of this repository is to continue evolving React Native core. We want to make contributing to this project as easy and transparent as possible, and we are grateful to the community for contributing bugfixes and improvements. Read below to learn how you can take part in improving React Native.
Code of Conduct
Facebook has adopted a Code of Conduct that we expect project participants to adhere to. Please read the full text so that you can understand what actions will and will not be tolerated.
Contributing Guide
Read our Contributing Guide to learn about our development process, how to propose bugfixes and improvements, and how to build and test your changes to React Native.
Open Source Roadmap
You can learn more about our vision for React Native in the Roadmap.
Good First Issues
We have a list of good first issues that contain bugs which have a relatively limited scope. This is a great place to get started, gain experience, and get familiar with our contribution process.
Discussions
Larger discussions and proposals are discussed in @react-native-community/discussions-and-proposals.
📄 License
React Native is MIT licensed, as found in the LICENSE file.
React Native documentation is Creative Commons licensed, as found in the LICENSE-docs file.